birkin



- UNITED STATES- PATENT omen.-

WILLIAM .A. G. BIRKIN, or Norm-scum, ENGLAND.

PROCESS or, AND SOLVENT FOR slim/mus PRECIOUS METALS mom THEIR REs.

SPECIFICATION fo ming part of Letters Patent No. 194,054,.dated March 21, 1893. p e Application filed was 21,1898. Serial no, 459,273.. (No specimens.)

To all whom it. may concern:

B it known that I, WILLIAM ACoUR'r GRANVILLE BIBKIN, a subject of the Queen of Great Brit-lam, residing at Nottingham, England, have invented new and'usetul Improvements inProcesses of and Solvents for Separating-Precious Metals from their Ores, of

which the following is a specification.

My invention relates to the extraction of metals, and particularly the precious metals, from their ores. v

It is the purpose of. my invention to provide a novel and simple process 'for the purpose named, whereby the pulverized'ores are subjected to the action of a solvent compound,

to dissolve the metals, which are afterward separatedfrom the solution in. any suitable manner.

My invention also has for its purpose the provision of a novel fluid-com pound especially adapted for the decomposition of the precious metals from the ores in which such metals are contained. p a

The invention consists, to these ends, in the process of treatment and in the novel fluidcompound hereinafter fully described and then more particularly pointed out and defined in the claims annexed to thisspecification.

To enable others skilled in the art to which my said invention pertains to fully understand and practice the same,I will proceed to describe said invention fully and in detail, andwill then indicate briefly the novel parts, or features thereof. In the practical use of my said invention I follow, in substantial respects, a mode of procedure consisting of the following steps: The ore is first pulverized to a suitable fineness, which will be controlled, usually, by the refractory character of the ore, the more unyielding being preferably reduced to a finely pulveri; edcondition. 'lhepulverizedorfinely divided ore is then placed in a menstruum consisting of potassium cyanide, and ferri-cyanide,in water, to which a suitable quantity of peroxide of hydrogen is added to intensify the acid reaction. The ore is subjected to agitation, while attacked by thissolution, by any or special proportion,

'or decanted, or otherwise separated from the mineral constituents of the ore, and'the values are eliminated eitherby preoipitation,'deposition, electrolysis, or by any method preferred for this purpose. i

Ilmay, and in some cases shall,'emplo heat 7 to aid and expedite the action of' the fluidcompound described in attacking the metals of the ores, but I do not limit my invention either to theuse, or to 'the absence, of this step.

I prefer to employ the tioned in about the proportions following, viz: 6 to one gallon of water I'use about three ounces of pot-assiu m cyanide, and with an equal quantity of water I mingle about one ounce of potassium ferri-c'yanide, 'Tethe'mixture of the.

two solutions named I add about five per cent. 7

of peroxide ot' hydrogeriI-tlrese proportions being regarded as preferable. This matter is subject to considerable variation, however, and I do not limit'myself to any particular,

What I claim' is p 7 1. In the art of separating metals from their ores, the process set forth which consistsin subjecting an ore, suitably comminuted to the action of a menstruum composed of potassium cyanide, potassium ferri-cyanide, and peroxide of hydrogen, in water, agitating the said ore, and finally separating the values out; of solution, substantially as described.

2. The fluid solvent for removing precious metalsifrom their ores, the same consisting of potassium cyanide, potassium terri-eyanide, and peroxide of hydrogen in water, in the proportionsspeci tied or thereabout, s u ljg'stantiall y as described. y

In'testirnony whereof I have h -e-reunto set my hand in presence of two subscribing witnesses.

WILLIAM A. o;' BIRKIN.

I Witnesses:

ALBERT H. N ORRIS, T. A. GREEN.

I ingredients men- 5 

